Wouldn’t it be great if you could have Facebook integration that acted similar to iOS’ built in Twitter integration? Well, now you can.

Introducing Fusion — a jailbreak tweak that integrates Facebook, Foursquare, and even MySpace (obligatory lol) into your default Twitter composition pane. But the tweak doesn’t stop there, it also allows you to composes messages for all of the aforementioned networks using Siri.

Check out our full video walkthrough on this awesome jailbreak tweak inside…

The wonderful thing about Fusion is that it’s a totally familiar and seamless experience. You don’t have to do or learn anything new; it just works.

If you’ve ever sent a tweet before from an iOS 5 device, you can update your Facebook status or Foursquare info the same way. It’s the tight integration with the existing mechanisms that make Fusion such a wonderful tweak.

I know a lot of people have been dying for Apple to put native Facebook integration into iOS — well, Fusion is the closest thing to that.

If you have an iPhone 4S, or have managed to get Siri running on an older device, it also comes bundled with an AssistantExtension plugin dubbed Furi. With Furi installed, you can compose posts destined for multiple social networks using only your voice.

As if all of that wasn’t enough, the expansion possibilities for Fusion are virtually unlimited as far as supported social networks go. You see; each network is simply a plugin, and additional plugins can be created by any developer. In other words, with Fusion, your $2.00 investment need not necessarily stop there.

For less than the price of a venti latte at your favorite Coffee joint, you can have built in Facebook integration that feels almost Apple like. If you’re a Facebook fan at least, I’d say we have a sure winner on our hands.

Fusion can be downloaded from Cydia’s BigBoss repo starting now. Let me know what you think about it in the comments below.